Ok to start with i need some help! I have a VZ sv6, 6spd (alloytec 190). So far i've given it an ss inductions CAI, despite what everyone thinks the honest result of this kit is a little (very little) low down (from idle type low down) sluggishness, a touch more punch from around 2500 - 5000, and not much change up top, and a much, much better induction noise! I'm not all that upset with the kit to be honest, a slightly bigger grin when you smash your mates XR, but nothing to wet your pants over. Now to what i'm here for, i would like some advice on what peoples opinions are when it comes to exhausts. I am strongly thinking pacemaker headers, decent cats, and 2 1/4 or 2 1/2 twin system right back to the tip. Has anybody tested out a similar sytem? If so what are your opinions, pro's, con's and cost! Eventually once exhaust is out of the way it'll get the computer played with and a 3.08 LSD to replace the single leggin 2.7ish whatever slug its got. Sorry to rant on so much, advice much apreciated, cheers.. :yeah:
If you have a CAI, you need a filter to match... Exhaust should liven things up abit but perhaps a tune to go with... I don't think on a internally stock engine getting bigger cats will do much... If you get a twin 2 1/2 your bottom end will not exist while you will get gains up high... Considering your not building a drag car but a street car (i'm assuming) then a single 2 1/2 would do the job. On the diff note... thats it rev @ in 6th @ 100kmph?? Cause a 3.45 (i think thats the ratio) LSD... that would leave a grin on your face! Till you rolled upto the servo to fill up anyway... Good Luck!
Gday mate. id suggest getting a 3.7 or a 3.9 LSD. My mate has an SV6 and is getting 3.9's, a tune, and a over the radiator intake similar to the ones on a v8, put in this tueday. The guy at enhanced automotive (sponser of this site) where my mate is getting it done said to go to 3.9's for sure. He said that everyone is always worried about how much highway driving they do, and if the revs are going to be sitting to high at around 100km/h. In reality if you are doing around 1000km - 2500km per year highway driving then thats not that much at all, id definately go 3.9's. He also made the point that if go ahead and get 3.45 or even 3.08 LSD your always going to be wishing you went that little bit further.
^^^ Unless the alloytec is somehow magical and doesn't use fuel... the 3.9 is going to throw fuel economy out the window... worst than if you got a v8! I went from a 3.08 to a 3.73 diff and i lost 50km per tank... Also my 1st gear was getting pretty damn short... If he's going from 2.7 to 3.91.. thats gonna be an insane change in km per tank! Unless you baby the thing all the time... in which case whats the point of getting a higher ratio anyway... Just a quick foot note... If you are currently running the 2.7 ratio diff and say (as an example) in 6th your revin @ 1500rpm @ 100kmph. After the 3.9 diff in the same situation you would be reving @ a touch under 2200rpm. When i got my diff done (granted in a ecotec with a few bolt-ons) i went from 3.08 to 3.73, my rpm in 5th @ 100kmph went from a touch under 2000 to 2450 odd and i lost 50km per tank using high octane fuel only...
Mate I wouldn't bother with the 3.08 ratio, the change will be minimal. Remember that you've got a 6spd gearbox...the ecotecs came out with a 3.08 and that was in a 4spd auto! That said, you don't wanna make your first gear too short, so I would recommend either a 3.46 or a 3.73 ratio. With a tune, this would give a great setup. As far as fuel economy goes, the question you really need to ask yourself is how much highway driving do you do? With a higher ratio your fuel economy around town will get better and you'll only be revving slightly higher on the freeway. As Jesterarts said, with a 3.9 ratio in your car you'd be revving a touch under 2200 rpm....which isn't very high at all! So with a 3.46 or 3.73 ratio you'd be fine! As mina_783 mentioned, I'm getting 3.9's put into my 5spd auto SV6 which I was doubtful about at first, but Brad from enhanced autimotive convinced me that it was a good choice. He knows his stuff and wouldn't recommend it if it was gonna be useless. Anyway mate that's my 2 cents, good luck with it all :thumbsup:
Yes I agree that the 3.46's are a good choice for the 5spd auto's but in the 6spd's 1st is quite a short gear already (i think from memory like 45-50km/h max, whereas Ive heard in the 5spds its more like 75-80km/h out of 1st) so I think going from 2.87's to 3.46's would basically cancel out using 1st in alot of cases. My thoughts in my car were to go something around 3.08 as well
good answers, 3.9 in the vz 6-speed is over the top, that will pretty well cancel out first gear, and as filtzy said it has an lsd allready so just do a crownwheel and pinion upgrade much more cost efficant way unless your centre is shagged on another note has any internal upgrades been released yet?
